In interference-affected reception areas, interference resulting, e.g., from multi-path propagation is clearly perceptible when a frequency-modulated (FM) station is received. A lesser perception of such interference can be achieved by decreasing the treble reproduction.
In some systems, this decrease in treble reproduction may be controlled by evaluating the received field strength and/or the reception quality, the transfer function of a filter in the audio signal branch being controlled in proportion thereto. In this context, the treble may be quickly canceled and also quickly switched back in.
In this connection, however, rapidly canceling the treble and switching it back may be disadvantageous in that reproduction of the interference cannot always and reliably be concealed, with the occurrence of noticeable and irritating effects such as “flutter.” In addition, with the conventional methods and circuit assemblages it may not be possible to coordinate the modification in treble reproduction with a reduction in channel separation.